Sensory modalities conveyed in the hindlimb somatic afferent input to nucleus tractus solitarius

Glenn M Toney, Steven W. Mifflin

Research output: Contribution to journalArticle

55 Citations (Scopus)

Abstract

To determine the somatic sensory modalities conveyed by hindlimb somatic afferent inputs, the discharge of neurons in the nucleus tractus solitarius was recorded in anesthetized rats after electrical stimulation of either the contralateral sciatic nerve or L6 spinal nerve, which innervates the hindlimb. The discharge of seven of eight cells was increased (P < 0.05) by capsaicin injected into the arterial supply of the hindlimb. Discharge was unaltered in 19 neurons tested for sensitivity to nonnoxious (40°C) and noxious (47°C) heating of the hindlimb skin. In contrast, lightly stroking the skin elicited discharge in 2 of 14 cells, whereas noxious pinching increased activity in 4 other cells. Rhythmic (1- to 3-s) muscle contraction (MC) increased (P < 0.05) discharge in >60% of neurons tested (11 of 18). Static (10- to 30-s) MC significantly (P < 0.05) increased discharge in four cells, two of which were also responsive to rhythmic MC. rhythmic and sustained muscle stretch increased discharge (P < 0.05) in three of eight neurons tested. These data indicate that nucleus tractus solitarius neurons receive input from low- and high-threshold cutaneous mechanoreceptors, respond to capsaicin delivered into the hindlimb arterial supply, lack thermal sensitivity, and respond to activation of mechanosensitive as well as metabosensitive ending in skeletal muscle.

Original languageEnglish (US)
Pages (from-to)2062-2073
Number of pages12
JournalJournal of Applied Physiology
Volume88
Issue number6
StatePublished - 2000

Fingerprint

Solitary Nucleus
Hindlimb
Neurons
Spinal Nerves
Mechanoreceptors
Capsaicin
Sciatic Nerve
Electric Stimulation
Skeletal Muscle
Hot Temperature
Muscles
Skin

Keywords

  • Exercise
  • Muscle contraction
  • Skeletal muscle
  • Skin
  • Thermal receptor

ASJC Scopus subject areas

  • Physiology
  • Endocrinology
  • Orthopedics and Sports Medicine
  • Physical Therapy, Sports Therapy and Rehabilitation

Cite this

Sensory modalities conveyed in the hindlimb somatic afferent input to nucleus tractus solitarius. / Toney, Glenn M; Mifflin, Steven W.

In: Journal of Applied Physiology, Vol. 88, No. 6, 2000, p. 2062-2073.

Research output: Contribution to journalArticle

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